What is the Biggest City in the World? Exploring Population, Area, and Urban Rankings

Determining the world’s largest city depends entirely on how “largest” gets defined. Population counts shift depending on whether researchers measure administrative city boundaries, metropolitan zones, or continuous urban agglomerations. According to UN-based data from the German Federal Statistical Office, Jakarta leads when measuring urban agglomerations, but Tokyo tops the rankings when using metropolitan definitions. This distinction shapes nearly every ranking available to researchers today.

Understanding these differences matters because city rankings carry real implications for urban planning, infrastructure investment, and policy decisions. The gap between Jakarta’s first-place agglomeration figure of 41.9 million and its metropolitan estimate of 12.4 million illustrates why definitions prove critical. Three major measurement approaches exist: city proper (administrative boundaries), metropolitan area (functional economic zone), and urban agglomeration (continuously built-up area including suburbs). Each produces dramatically different results.

Beyond measurement variations, the world’s urban landscape is undergoing a fundamental shift. Asia and Africa now dominate growth patterns, with Dhaka projected to surpass Jakarta as the largest urban agglomeration by 2050. These demographic changes reshape global conversations about resource allocation, climate adaptation, and urban development strategies.

What is the largest city in the world by population?

Jakarta holds the top position in 2025 according to UN agglomeration data, with 41.9 million residents. The Indonesian capital has experienced sustained growth that accelerated in recent decades, reflecting broader patterns of urbanization across Southeast Asia. Dhaka follows closely at 36.6 million, with projections suggesting it will exceed 52 million by 2050, representing a 42.3% increase from current levels.

Overview: World’s Largest Cities in 2025

Key Insights on the World’s Largest Cities

• Jakarta overtaken Tokyo as the largest urban agglomeration by 2025, marking a historic demographic shift toward South and Southeast Asia
• 33 cities currently exceed 10 million residents, with 19 of those located in Asia
• Global urban population stands at 4.8 billion of 8.2 billion total world population—58%—a figure projected to reach 67% by 2050
• Rankings depend heavily on definitions: Jakarta ranks #1 by agglomeration but #19 by metro area, while Tokyo reverses this pattern
• Dhaka shows the fastest growth trajectory, projected to reach 52.1 million by 2050, potentially becoming the world’s largest
• African megacities like Kinshasa and Lagos are expanding rapidly, though data coverage remains less comprehensive than for Asian cities
• 37 megacities projected by 2050, up from 33 today, reflecting accelerating global urbanization

Top 10 Cities by Urban Agglomeration (2025)

Data sourced from UN-based statistics compiled by the German Federal Statistical Office.

What is the largest city in the world by area?

Defining the largest city by land area proves more challenging than population measurements. Comprehensive 2025 data remains scarce, with the most reliable figures dating to 2015 urban area measurements. When examining contiguous urban areas rather than administrative boundaries, Chinese metropolitan regions dominate. Guangzhou-Foshan covers approximately 3,432 square kilometers, while the Osaka-Kobe-Kyoto corridor spans roughly 3,212 square kilometers.

How Area Definitions Affect Rankings

Area measurements face the same definitional challenges as population counts. Administrative city boundaries often bear little relationship to where urban development actually occurs. When researchers measure contiguous built-up areas, single administrative jurisdictions frequently expand to encompass multiple cities. This explains why figures for Chinese metropolitan regions appear so large compared to traditional city boundaries.

Top 10 largest cities in the world

The most widely cited rankings for largest cities come from two main approaches. The UN agglomeration methodology, used by the German Federal Statistical Office, emphasizes continuous urban development including suburban zones. Alternative metro-area measurements, as compiled by Ontario Tech University, prioritize functional economic regions and produce different rankings entirely.

Metro Area Rankings (2025)

This metro-style ranking from Ontario Tech University places Tokyo at the summit with 36.4 million residents. Notably, Jakarta drops to 19th position at 12.4 million under this narrower definition, illustrating how measurement methodology fundamentally alters perceived city size.

Source Variations and Data Conflicts

Different authoritative sources produce conflicting rankings because each prioritizes different urban definitions. Wikipedia’s List of Largest Cities emphasizes that definitions matter critically when comparing cities. The UN agglomeration standard captures suburban expansion better, while metro measurements better reflect economic integration. Neither approach is incorrect—they simply answer different questions about urban form.

Top 10 largest cities in the world by area

Limited comprehensive data exists for 2025 area rankings. Historical urban area measurements from Worldometers suggest Chinese metropolitan regions and Japanese urban corridors dominate land area measurements, while South Asian cities like Mumbai achieve the highest population densities despite relatively modest geographic footprints.

Population Density: A Different Perspective

Density measurements offer another lens for understanding urban scale. Mumbai demonstrates extreme density at approximately 32,400 residents per square kilometer within its 546 square kilometer municipal area. This figure contrasts sharply with the sprawling Chinese metropolitan regions where lower densities extend across thousands of square kilometers.

Evolution of the World’s Largest Cities

Historical city size rankings reveal a shifting global urban landscape spanning more than two centuries. The progression from London and Beijing in the 1800s through Tokyo’s dominance in the late 20th century to Jakarta’s emergence in 2025 reflects broader patterns of economic development, colonial history, and contemporary urbanization trends.

1. 1800s: London and Beijing served as the world’s largest urban centers during the industrial revolution’s early phases, each holding populations exceeding one million
2. 1950s: Tokyo began ascending toward global urban primacy as Japan’s post-war economic miracle transformed the metropolitan region
3. 1980s–2000s: Tokyo consolidated its position, consistently ranking first with figures exceeding 30 million across various measurement approaches
4. 2010s: Asian megacities outside Japan began accelerating, with Jakarta, Delhi, and Shanghai showing particularly strong growth trajectories
5. 2025: Jakarta surpassed Tokyo using agglomeration methodology, while Dhaka emerged as the fastest-growing megacity globally
6. 2050 (Projected): Dhaka anticipated to reach 52.1 million, potentially becoming the world’s largest urban agglomeration, with Kinshasa and Lagos also expanding rapidly

Population vs Area: Defining “Biggest”

The question “What is the biggest city in the world?” lacks a single definitive answer precisely because “biggest” admits multiple valid interpretations. Researchers and policymakers often need different metrics depending on their specific questions about urban systems.

Why Rankings Change: Urban Growth Factors

Multiple factors drive the shifts in city rankings observed over recent decades. Economic globalization concentrated employment opportunities in specific urban centers, while improvements in transportation and communication enabled cities to expand geographically while maintaining economic integration. Natural population growth, rural-to-urban migration, and administrative boundary changes all contribute to measured population fluctuations.

Climate considerations increasingly influence urban growth patterns. Coastal cities like Jakarta face subsidence and flooding challenges that could reshape long-term settlement patterns. Meanwhile, inland cities in South Asia and sub-Saharan Africa benefit from continued population growth that drives their expansion toward megacity status. These factors suggest continued reconfiguration of global city hierarchies through the mid-21st century.

Data from Official Sources

Researchers examining urban rankings should consult multiple authoritative sources while understanding each database’s specific methodology. The German Federal Statistical Office provides comprehensive UN-based agglomeration data, while academic institutions like Ontario Tech University offer alternative metro-area compilations. Both approaches contribute valid insights about different aspects of urban form.

The discrepancy between Jakarta’s 41.9 million agglomeration figure and 12.4 million metro figure—reported by different sources using different definitions—demonstrates why single rankings prove insufficient for understanding global urbanization. Informed interpretation requires recognizing these methodological differences rather than treating any single figure as definitive.

“Rankings vary by definition (urban agglomeration vs. metro area) and source, with Tokyo topping some city proper lists.”

— German Federal Statistical Office / UN Data

Future Projections for Megacities

Projections from UN sources suggest continued transformation of the global urban landscape through 2050. Dhaka’s anticipated growth to 52.1 million reflects broader patterns of South Asian urbanization, while African megacities including Kinshasa and Lagos show similarly rapid expansion trajectories. Simultaneously, Japanese and South Korean cities show modest projected declines, suggesting demographic stabilization or contraction in regions with aging populations.

The broader urbanization trend points toward a world where 67% of humanity lives in urban areas by 2050, up from 58% today. This shift carries profound implications for infrastructure investment, environmental sustainability, and governance structures. Cities that successfully adapt to these pressures will likely dominate future rankings, while those that fail may see their positions decline regardless of current standings.

Summary

The world’s largest city depends entirely on measurement methodology. Jakarta leads using UN urban agglomeration definitions, while Tokyo dominates metropolitan area rankings. For population-based comparisons, Dhaka shows the fastest growth trajectory and is projected to claim the top position by 2050. Area measurements remain less systematically documented, with Chinese metropolitan regions showing the largest geographic footprints and South Asian cities demonstrating the highest densities. Understanding these distinctions allows for informed interpretation of various rankings available from official sources. For those interested in broader development contexts, understanding construction costs provides insight into the infrastructure pressures facing these growing urban centers.

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